The area central control unit can be used for controlling operating devices for lighting means (sources), and are used in lighting systems for switching lighting means on and off and for setting the brightness. Normally, the lighting means are controlled by operating devices. The operating devices are combined to form groups and can be controlled by one or more central control units. The term lighting means refers to both gas discharge lamps as well as halogen lamps or light emitting diodes (LEDs). The lighting means can be disposed individually or collectively with other lighting means in a lamp, which can also contain the operating device.
With modern lighting systems, analog or digital control commands are frequently transmitted to the operating device by the central control unit. In particular, brightness values can be indicated by these external control commands in order to obtain various lighting states.
An analog control command can be a control voltage, for example, that can be modulated in terms of the amplitude.
The operating devices can be provided with an address in order to enable individual or group control by the central control unit.
A widely used control method is to control lighting systems according to the DALI (Digital Addressable Lighting Interface) standard. This standard defines an interface and a transmission format for digital control of operating devices, wherein addresses can be assigned to the individual operating devices. The operating devices can be switched on and off or controlled in terms of brightness via the external control commands. Furthermore, a special operating condition such as an emergency lighting state can be initiated, and error messages can be retrieved.
The DALI standard is a 16 bit Manchester code, which enables a maximum dimming speed of just 0.7 seconds in a brightness change of 1% to 100%. The maximum level lies in a range of approximately 16V, the minimum level is at a voltage of approximately 0 volts.